At least 1.5 GB of RAM (though 4 GB+ is recommended for smooth play). Graphics: 256MB VRAM (GeForce 7900 or Radeon X1900). Where to Safely Buy GTA IV

Unofficial compressed downloads are frequently bundled with malware, miners, or trojans. System Requirements

The legitimate Grand Theft Auto IV: The Complete Edition on Steam has a download size of approximately 19.70 GB . A 7.51 GB file is heavily compressed and may be missing essential game files like audio or cutscenes to achieve that size.

If you are checking if your PC can handle the game, the requirements are relatively low by modern standards: Windows 7 or newer.